SIGGRAPH Authors Seminar Series at I2R
Seminar 9
Title: Sampling
and Reconstruction of High-Dimensional Visual Appearance
Speaker: Prof Ravi Ramamoorthi, University of
California, Berkeley
Chaired
by: Dr Ng Tian
Tsong
Venue:
Time: 10:00-11:00, 25 Jan 2011, Tuesday
Abstract
In this talk, we describe new approaches to many
current and classic problems in computer graphics. This includes the challenge of creating
realistic images at interactive rates, for real-time rendering applications
like games and virtual design applications.
Another important component of visual realism is the realistic modeling
of surface appearance, for objects like clothing, or phenomena like smoke. In both domains, data-driven methods are
increasingly being used, wherein the properties of a real scene are measured,
or the properties of a virtual scene are simulated, and then reused to create
new imagery. Even classical computer
graphics rendering can be viewed in this light, wherein one is making use of
samples of the virtual scene, corresponding to a particular point in space or
an image pixel, and moment in time.
A key challenge in data-driven visual appearance is its high
dimensionality. For example, the
appearance of a human face requires understanding the variation across the
surface, all lighting directions, and viewpoints that can be a 6D space. Similar high-dimensional spaces arise in
real-time and offline rendering, as well as in image acquisition
applications. The challenge of sampling
and reconstructing these high-dimensional datasets has been a major obstacle in
computer graphics. In this talk we
detail a research program that seeks to develop new sparser sampling
strategies, coupled with novel signal processing tools for reconstruction. We describe examples in three different
areas: real-time rendering of area lighting, appearance acquisition of
volumetric media, and Monte Carlo rendering of motion blur. I will also briefly discuss recent efforts in
the imaging domain. These examples
indicate the potential of a broad program across computer graphics for
fundamentally new strategies to acquire and exploit visual appearance data.
Bio-data
Ravi Ramamoorthi has been an
associate professor of electrical engineering and computer science at the
University of California, Berkeley, since January 2009. Earlier, he was on the faculty of the
computer science department at Columbia University, which he joined after
receiving his PhD from Stanford University in 2002. His research interests span many areas of
computer graphics rendering and appearance, as well as related problems in
physics-based computer vision. His focus
has been on developing new computational models and signal-processing methods
to understand and make use of complex visual appearance. His work has been recognized with many
honors, including the ACM SIGGRAPH Significant New Researcher Award, and the
white house's Presidential Early Career Award for Scientists and Engineers, as
well as young investigator awards from NSF, ONR and the Sloan foundation.
Seminar 8
Title: Dynamic Models for Character Animation
Speaker: Dr Yin KangKang,
Chaired by: Dr Huang Zhiyong
Venue:
Time: 14:30-15:10, October 1, Friday, 2010
Abstract
This talk presents three examples of our efforts to
develop more sophisticated dynamic models of human motion. We first show short
demos of a remarkably simple and effective balance mechanism for bipeds, and
continuation methods to generalize basic locomotion skills to more challenging
tasks. We then present our latest work on sampling-based motion control. We
demonstrate fast control reconstruction for a diverse set of captured motions,
including walking, running, and contact-rich tasks such as sideways rolling and
kip-up jumps. The proposed method can also generate physically plausible motion
variations, and perform physically based motion transformation and retargeting.
In addition, we show that sampling is effective for reference-trajectory-free
scenarios, such as idling.
Bio-data
KangKang Yin obtained her PhD from the
Seminar 7
Title: K-set tilable surfaces
Speaker: Dr Fu Chi
Wing, Nanyang Technological University
Chaired by: Dr Huang Zhiyong
Venue:
Time: 14:00-14:40, June 2, Wednesday, 2010
Abstract
In this talk, I will introduce a geometric optimizing
method for tiling on a quad-mesh. Given a quad-based surface, our goal is
to generate a set of K quads whose instances can produce a tiled surface that
approximates the input surface. This research work proposes the K-set tilable surface, which can lead to an effective cost
reduction in the physical construction of the given surface. Rather than
mildewing lots of different building blocks, a K-set tilable
surface requires the construction of K prefabricated components only. At
the end of this talk, I will demonstrate K-set tilable
surfaces on various surfaces, including some that mimic the exteriors of
certain renowned building landmarks.
Bio-data
Chi-Wing FU received his B.Sc. and M.Phil.
degrees in Computer Science and Engineering from the Chinese University of Hong
Kong in 1997 and 1999, respectively, and later his PhD degree in Computer
Science from Indiana University in Bloomington in December, 2003. He held previous visiting assistant professor
positions in Hong Kong University of Science and Technology and joined
Seminar 6
Title: Research in Visual Computing
Speaker: Prof Heng Pheng Ann, The
Chaired by: Dr Huang Zhiyong
Venue: Resonance @ 13N, Fusionopolis
Time: 10:30-11:30, November 5, Wednesday, 2008
Abstract
The Virtual Reality, Visualization and
Bio-data
Dr. Heng received his B.Sc in computer science in 1985 from the National
University of Singapore. He received his M.Sc in
computer science, M.A. in applied mathematics, and Ph.D. in computer science
from
He has served as the Director of Virtual Reality,
Visualization and Imaging Research Centre at CUHK since 1999 and as the
Director of Centre for Human-Computer Interaction at Shenzhen Institute of
Advanced Integration Technology,
His current research interests include virtual reality
applications in medicine, visualization, medical imaging, human-computer
interaction, and computer graphics.
Seminar 5
Title: Appearance Manifolds for Modeling Time-Variant
Appearance of Materials
Speaker: Dr
Steve Lin, Leader Researcher, Microsoft Research
Chaired by: Dr Huang Zhiyong
Venue: Three star Theatrette
Time: 11-11:40, May 16, Friday, 2008
Abstract
We present a visual simulation technique
called appearance manifolds for modeling the time-variant surface appearance of
a material from data captured at a single instant in time. In modeling
time-variant appearance, our method takes advantage of the key observation that
concurrent variations in appearance over a surface represent different degrees
of weathering. By reorganizing these various appearances in a manner that
reveals their relative 
order with respect to weathering degree, our method
infers spatial and temporal appearance properties of the material’s weathering
process that can be used to convincingly generate its weathered appearance at
different points in time. Results with natural non-linear reflectance
variations are demonstrated in applications such as visual simulation of
weathering on 3D models, increasing and decreasing the weathering of real
objects, and material transfer with weathering effects.
Bio-data
Steve joined Microsoft Research Asia in
June 2000, and is currently a Lead Researcher in the Internet Graphics group.
His research interests lie in the fields of computer
vision and computer graphics. In computer vision, his primary research areas
are photometric analysis and low-level vision. His interests in computer
graphics include reflectance modeling and inverse rendering. He received a
B.S.E. in electrical engineering from
Seminar 4
Title: MoXi Digital Paint
Speaker: Dr. Nelson
Chu, HKUST, Visiting Fellow, NTU
Chaired by: Dr Huang Zhiyong
Venue: Big-One
Time: 11-11:40, April 25, Friday, 2008
Abstract
Chinese painting and calligraphy are among
the oldest continuous art traditions in the world. The expressive brush strokes
and the fascinating ink dispersion contribute a lot to the universal appeal. In
this talk, I will first outline our physically-based methods to model brush
dynamics and ink dispersion. Our goals are to bring the distinct charm of ink
painting and calligraphy to the digital art scene and to further develop the
art traditions. The second part of the
talk would be a brief discussion on our collaboration with the industry,
followed by live demo.
Bio-data
Nelson Chu is both a visual artist and a
software engineer. From 2001 to 2007, he focused on the research and
development of a novel digital paint system, which redefined
"natural-media painting" in the field of Computer Graphics. The
resultant system attracted industrial giants Adobe and Sony, who licensed the
technology in 2006 and 2007 respectively. Nelson was born in Hong Kong and
raised in
Seminar 3
Title: ShapePalettes: a novel approach for 3D markup
Speaker: Dr
Michael S. Brown, Sung Kah Kay Assistant
Professor, SOC, NUS
Chaired by: Dr Huang Zhiyong
Venue: Three star Theatrette
Time: 11:30-12:10, March 28, Friday, 2008
Abstract
This talk overviews a simple interactive
approach to specify 3D shape in a single view using "shape palettes".
The interaction is as follows: draw a 2D primitive in the 2D view and then
specify its 3D orientation by drawing a corresponding primitive on a shape
palette. The shape palette is presented as an image of some familiar shape
whose local 3D orientation is readily understood and can be easily marked over.
The 3D orientation from the shape palette is transferred to the 2D primitive
based on the markup -- only sparse markup is needed to generate expressive and
detailed 3D surfaces. This markup approach can be used to model freehand 3D
surfaces drawn in a single view, or combined with image-snapping tools to quickly
extract surfaces 
from images and photographs.
The talk will be followed by a short discussion on how the ShapePalette
idea emerged and its road to acceptance as a full paper at SIGGRAPH'07.
Bio-data
Michael S. Brown received his BS (1995)
and PhD (2001) from the
Seminar 2
Title: Image-based Tree Modeling
Speaker: Dr
Tan Ping, Assistant Professor, ECE, NUS
Chaired by: Dr Huang Zhiyong
Venue: Big-One
Time: 11-11:40, March 7, Friday, 2008
Abstract
In this talk, we present a technique for
generating 3D texture mapped tree models from images. From these images, a set
of 3D points and camera poses are computed with existing technique. Our method
will compute a texture mapped triangle mesh model from these recovered 3D
points and images. To faithfully model different trees with large and small
leaves, we designed different approaches. For trees with relatively large
leaves, segmentation is performed in both image and 3D spaces. Using the
segmented image and 3D data, the geometry of each individual leaf is then
automatically recovered from the multiple views by fitting a deformable generic
leaf model. For trees with relatively small leaves, we do not model each leaf
directly from images due to the large leaf count, small image footprint, and
widespread occlusions. Instead, we populate the tree with leaf replicas from
segmented source images to reconstruct the overall tree shape. In addition, we
use the shape patterns of visible branches to predict those of obscured
branches. We demonstrate our approach on a variety of trees.
Bio-data
Ping Tan received the B.S. degree in
Applied Mathematics from
Seminar 1
Title: Towards High Quality 3D Modeling
Speaker: Dr Zheng
Jianmin, Assistant Professor, SCE, NTU
Chaired by: Dr Susanto Rahardja,
Director and Department Head
Venue: Big-One
Time: 5-5:40, February 26, Tuesday, 2008
Abstract
As an important component of digital 3D content,
geometric models are nowadays more and more pervasive, from traditional
engineering applications such as computer-aided design and manufacture
(CAD/CAM), robotics and physical simulations to multimedia applications
including e-commerce, cultural heritage, 3D games, animation and special
effects in motion pictures. However, creating and processing such 3D models are
generally labor-intensive and time-consuming, especially when the shapes are
geometrically and topologically complex. Therefore new theoretical insights and
practical algorithms for efficient, flexible and intuitive 3D shape modeling
and processing are highly required. In this talk, I will share some of my
thoughts on high quality 3D modeling and present some of our research work in
this area.
Bio-data
Jianmin Zheng
is an assistant professor in the
